Fuel gases, such as natural gas and hydrogen gas, are promising alternatives to the traditional petrol-based energy sources consumed by motor vehicles. Such fuel gases generally burn cleaner than traditional petroleum-based gasoline and diesel fuels and, thus, are better for the environment. One challenge encountered with the use of fuel gases, however, is how to store a sufficient amount of fuel gas on-board an automotive vehicle so that reasonable driving distances can be achieved between fill-ups. To this end, two storage approaches are typically employed when attempting to satisfy mobile on-board vehicle fuel gas storage needs: storing fuel gas in a compressed state or a solid state. When stored in a compressed state, the fuel gas is compressed and stored at a high pressure within the tank, typically at a pressure in excess of 200 bar. And when stored in a solid state, the fuel gas is stored on a fuel gas storage material that increases the volumetric and gravimetric energy density of the gas within the available tank space such that it compares favorably to compressed fuel gas but at a much lower pressure.
A design consideration that factors into the commercial demand and viability of on-board fuel gas storage tanks is “conformability.” The concept of tank conformability relates to the design flexibility of the tank structure and how easily it can be adapted to fit the available packing requirements across many different vehicle platforms. The fuel gas storage tanks employed to date—for both compressed and solid state fuel gas storage—have largely been shaped as cylinders or spheres and are oftentimes made of thick and/or heavy materials. These tank constructions have been used to resist the forces exerted by the associated pressures from inside the tanks. But cylindrically- and spherically-shaped storage tanks are generally considered to be non-conformable since they do not always satisfy packaging requirements demanded in automotive vehicles and/or they are unable to fully utilize the space designated for the tank on a vehicle platform.
As such, there exists a need for a fuel gas storage tank that not only stores a sufficient quantity of fuel gas to enable acceptable driving distances between fill-ups, but is also conformable to many different types of vehicle platforms. A fuel gas storage tank that possesses such attributes would simplify the integration of fuel gas, such as natural gas and hydrogen gas, into motor vehicles—especially passenger cars and trucks—as a source of power for operating and propelling the vehicle either alone or in combination with other power sources such as, for example, traditional petrol-based fuels (e.g., gasoline or diesel fuel) and lithium ion batteries. And, practically speaking, the flexibility and design freedom to customize the size and shape of the fuel gas storage tank to fit individual vehicle packaging requirements would also make fuel gas technologies a more economically attractive option for motor vehicle applications.